Objectives: This study attempted to determine the incidence, prognosis and predictability of postoperative left ventricular dysfunction in patients undergoing correction of mitral regurgitation.
Background: Left ventricular function in patients with mitral regurgitation is altered by loading conditions and is difficult to assess. Predictive value of preoperative variables on postoperative left ventricular function and the role of echocardiography are uncertain.
Methods: In 266 patients undergoing correction of mitral regurgitation between 1980 and 1989, left ventricular function was echocardiographically assessed preoperatively (within 6 months) and postoperatively (within 1 year).
Results: After correction of mitral regurgitation, left ventricular ejection fraction decreased significantly ([mean +/- SD] 50% +/- 14% vs. 58% +/- 13%, p < 0.0001). Postoperative left ventricular dysfunction (ejection fraction < 50%) was frequent (41% of patients) and carried a poor prognosis (at 8 years survival, 38% +/- 9% vs. 69% +/- 8%, p < 0.0001). Four preoperative echocardiographic variables showed good correlation with postoperative ejection fraction: preoperative ejection fraction (r = -0.70), systolic diameter (r = -0.63), diameter/thickness ratio (r = -0.64) and end-systolic wall stress (r = -0.62) (all p < 0.0001). With multivariate analysis, ejection fraction (p = 0.0001) and systolic diameter (p = 0.0005) were independent predictors of postoperative ejection fraction, and angiographic variables provided no incremental predictive power. In addition to echocardiographic variables, recent regurgitation, functional class and coronary artery disease were also independent predictors of postoperative ejection fraction.
Conclusions: After surgical correction of mitral regurgitation, left ventricular dysfunction is frequent and carries a poor prognosis. Postoperative ejection fraction can be predicted by echocardiographic preoperative ejection fraction and systolic diameter. Recent onset of regurgitation, mild or no symptoms, and absence of coronary artery disease are independent and favorable predictors of postoperative ejection fraction. These results should lead to consideration of surgical correction at an earlier stage.